Inhibition of amniotic prostaglandin E release by ampicillin.

Abstract

The effect of antibiotics in the prevention of preterm labor needs to be further investigated. The aim of this study was to determine the effect of ampicillin on prostaglandin E release from amnion as a possible explanation for its ability to retard preterm labor. The effect of the beta-lactam antibiotic ampicillin on prostaglandin E release from human amnion was tested under basal and stimulated conditions. Ampicillin dose dependently inhibits basal prostaglandin E release from amnion in both static and dynamic conditions. In our experiments, 10(-7) mol/L ampicillin (a concentration able to significantly inhibit prostaglandin E output) leaves the microbiologic features of the medium substantially unmodified up to 5 hours of incubation. Moreover, the drug reversibly counteracts the prostaglandin E elevation induced by arachidonic acid or oxytocin. This finding (i.e., that ampicillin inhibits prostaglandin E release from amnion) may offer an explanation for a beneficial response to ampicillin therapy in the case of preterm labor even in the absence of bacterial infection.